JP2004299277A - Ink-jet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cover to seal a discharge face of a recording head for a long time without swelling or dissolution even when an ultraviolet curing type ink is used as ink. <P>SOLUTION: An ink-jet printer (100) includes a recording head (3) where discharge openings for discharging the ink are set at the discharge face, and a suction device (4) for sucking the ink from the discharge openings. The suction device (4) has a suction cap (5) which covers the discharge openings of the recording head (3) to tightly adhere to the discharge face (31) at the suction time of ink, and separates from the discharge face (31) at the non suction time. The suction cap (5) is formed of an elastic material with a swelling resistance or dissolution resistance to the ink. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink jet printer.
[0002]
[Prior art]
In an ink jet printer, an ejection port for ejecting ink to a recording medium is provided on an ejection surface of a recording head. In the print head, an increase in the viscosity of the ink, clogging of the discharge port due to the sticking of the ink, or clogging due to bubbles or dust generated in the ink flow path leading to the discharge port occurs. Therefore, after covering the ejection surface of the recording head with a suction cap made of rubber or silicone, the suction surface of the recording head is suctioned by a suction pump, so that air bubbles and ink remaining in the ejection port are sucked. In addition, dust or the like attached to the ejection surface is removed, and the ejection surface of the recording head is maintained (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent No. 3233212
[Problems to be solved by the invention]
However, when an ultraviolet curable ink, particularly one containing a cation polymerizable compound, is used as the ink for the ink jet printer, as the suction cap formed of rubber or silicon comes into contact with the cation polymerizable compound, the time elapses. It swells or dissolves, making it impossible to completely seal the ejection surface of the recording head, making it impossible to apply a negative pressure to the ejection surface of the recording head, making it difficult to suck air bubbles and ink in the ejection openings Met.
[0005]
Therefore, an object of the present invention is to provide an ink jet printer that can cover the ejection surface of a recording head in a sealed manner for a long time without swelling or dissolving even when an ultraviolet curable ink is used as the ink. That is.
[0006]
[Means for Solving the Problems]
In order to solve the above problem, an invention according to claim 1 is an ink jet printer including a recording head having an ejection port for ejecting ink on an ejection surface, and a suction device for sucking ink from the ejection port. The suction device may further include a suction cap that covers the discharge port of the recording head and is in close contact with the discharge surface when the ink is sucked, and is separated from the discharge surface when the ink is not suctioned. And molded from an elastic material having swelling resistance or dissolution resistance to the ink.
[0007]
According to the first aspect of the present invention, since the suction cap is formed from an elastic material having swelling resistance or dissolution resistance to ink, the suction cap does not swell or dissolve with ink, and the recording head To prevent air from flowing in between the air and the suction cap. In other words, when suctioning ink, it is possible to reliably suck air bubbles and ink in the ejection ports while applying a negative pressure to the ejection ports of the recording head. A stable image can be output.
[0008]
According to a second aspect of the present invention, in the ink jet printer according to the first aspect, the suction cap has a protruding portion that is in close contact with the ejection surface of the recording head when the ink is sucked.
[0009]
According to the second aspect of the present invention, since the suction cap has the ridge portion that comes into close contact with the ejection surface of the recording head when sucking ink, the recording head is compared with a case where the entire suction cap is brought into close contact with the recording head. , The adhesion of the recording head to the ejection surface can be improved.
[0010]
According to a third aspect of the present invention, in the inkjet printer according to the first or second aspect, the suction device includes a cap holder that supports the suction cap, and prevents the suction cap from dropping from the cap holder. Characterized in that a falling-off prevention mechanism is provided.
[0011]
According to the third aspect of the present invention, since the drop-off prevention mechanism for preventing the suction cap from dropping from the cap holder is provided, the suction cap does not drop from the cap holder. Therefore, the reliability as a suction cap is improved, and a stable image can be output as an ink jet printer.
[0012]
According to a fourth aspect of the present invention, in the ink jet printer according to the third aspect, the falling-off prevention mechanism is formed on an overhang formed along a side surface of the suction cap and on an upper surface of the cap holder, And a receiving part for receiving the overhanging part.
[0013]
According to the fourth aspect of the present invention, since the protrusion of the suction cap is received by the receiving portion of the cap holder, the movement of the suction cap is regulated by the cap holder. The suction cap does not fall off the cap holder due to vibration or the like.
[0014]
According to a fifth aspect of the present invention, in the ink jet printer according to any one of the first to fourth aspects, the ink is an ultraviolet curable ink containing a cationically polymerizable compound.
[0015]
According to the fifth aspect of the present invention, even when the illuminance of ultraviolet rays is relatively small, the composition is sufficiently cured, and the deterioration of image quality can be suppressed.
[0016]
According to a sixth aspect of the present invention, in the ink jet printer according to the first to fifth aspects, the suction cap is formed from a perfluoroelastomer.
[0017]
According to the invention as set forth in claim 6, since the suction cap is formed from a perfluoroelastomer, the suction cap does not swell or dissolve even when ultraviolet curable ink is used, so that the recording head can be used. In the case of sucking the ink of the ejection port, the bubbles and the ink in the ejection port of the nozzle can be reliably sucked, so that a stable image can be output as an ink jet printer.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an inkjet printer according to the present invention will be described in detail with reference to the drawings.
[0019]
As shown in FIG. 1, the inkjet printer 100 includes a guide rail 1 extending in a direction orthogonal to a recording medium conveyance direction, and a carriage 2 provided on the guide rail 1 and reciprocating in a direction in which the guide rail 1 extends. I have. The carriage 2 is equipped with a plurality of recording heads 3 for discharging ink onto a recording medium, and the recording head 3 can reciprocate on the image forming area T as the carriage 2 moves.
[0020]
A plurality of (four in the present embodiment) recording heads 3 are provided according to the types of ink (Y: yellow, M: magenta, C: cyan, K: black) used in the ink jet printer 100. A plurality of ejection openings for ejecting ink are formed on the ejection surface 31 of the head 3.
[0021]
At one end of the movement area of the carriage 2, a maintenance area M for performing maintenance of the recording head 3 is provided, and a suction device 4 for sucking ink remaining in the recording head 3 after printing is provided in the maintenance area M is provided. Have been.
[0022]
As shown in FIG. 2, the suction device 4 covers the discharge port of the recording head 3 when suctioning ink and is in close contact with the discharge surface 31, and separates from the discharge surface 31 during non-suction, and the suction cap 5. And a suction pump 7 for sucking ink from the ejection openings of the recording head 3.
[0023]
As shown in FIG. 3, the suction cap 5 is formed to be substantially oval and endless, and is formed from a perfluoroelastomer. This perfluoroelastomer is suitable as the suction cap 5 because it has elasticity and does not swell or dissolve even when it comes into contact with an ultraviolet curable ink containing a cationically polymerizable compound.
[0024]
The suction cap 5 that is in close contact with the ejection port of the recording head 3 when suctioning the ink remaining on the recording head 3 is formed in a semicircular shape in cross section, and the upper end thereof is formed as a ridge 51. Further, at the lower end of the suction cap 5 supported by the cap holder 6, an outwardly protruding portion 52 is formed along the side surface of the suction cap 5.
[0025]
As shown in FIGS. 2 and 4, the cap holder 6 is formed in a rectangular parallelepiped shape, for example, from a metal material such as aluminum, and has a receiving portion for receiving a projecting portion 52 formed on the suction cap 5 on its upper surface. 8 are formed. As shown in FIG. 2, the receiving portion 8 includes a groove 81 formed on the upper surface of the cap holder 6, a recess 82 formed to extend substantially horizontally from the bottom of the groove 81, and receiving the overhang 52. , An escape portion 83 formed to extend in a direction opposite to the concave portion 82.
[0026]
By fitting the suction cap 5 into the receiving portion 8, the groove 81 regulates the horizontal movement of the suction cap 5, and the concave portion 82 regulates the vertical movement of the suction cap 5. That is, the protrusion 52, the groove 81, and the recess 82 constitute a mechanism for preventing the suction cap 5 from falling off. The escape portion 83 receives a part of the suction cap 5 when the suction cap 5 is elastically deformed. By forming the escape portion 83, when the suction cap 5 is brought into close contact with the recording head 3, the elastically deformed suction cap 5 moves toward the groove 81, so that the suction cap 5 is not twisted.
[0027]
An ink suction pipe 71 penetrating through the cap holder 6 is connected below the cap holder 6, and a suction pump 7 is provided in the middle of the ink suction pipe 71.
As shown in FIG. 2, the suction pump 7 is provided below the cap holder 6, and is connected to an ink suction pipe 71 provided through the cap holder 6. Further, a waste ink tank 72 for discharging the sucked ink is connected to the suction pump 7.
[0028]
Further, next to the suction device 4, an ink absorbing device 9 for wiping the ink of the recording head 3 is provided.
As shown in FIG. 1, the ink absorbing device 9 includes a sheet-shaped ink absorber 91, a first roll shaft 92, a second roll shaft 93 around which the ink absorber 91 is wound, and a first roll shaft. A heater 94 provided between the second roll shaft 93 and the lower surface side of the ink absorber 91 and an ultraviolet irradiator for irradiating the ink absorber 91 with ultraviolet light on the second roll shaft 93 side 95 and a roll shaft drive mechanism (not shown).
[0029]
An ink absorber 91 is wound around the first roll shaft 92 and the second roll shaft 93, and the first roll shaft 92 and the second roll shaft 93 are driven by a roll shaft driving mechanism. Thus, the ink absorber 91 sent from the first roll shaft 92 is wound around the second roll shaft 93.
[0030]
The heater 94 warms the ink absorber 91 from the lower surface side, and can heat the ink absorber 91 from about 30 ° C. to about 60 ° C.
[0031]
Ultraviolet irradiation unit 95, LED and for outputting the ultraviolet light, and the like extending out the optical fiber from an ultraviolet output device can output a UV 30 mJ / cm ² of at least 1 mJ / cm ^2.
[0032]
Next, the ink will be described.
The ink is an ultraviolet curable ink having a property of being cured by irradiation with ultraviolet light, and includes at least a polymerizable compound (including a known polymerizable compound), a photoinitiator, and a coloring material as main components. Has a viscosity of 10 to 500 mPa at 30C.
[0033]
UV-curable inks are roughly classified into radical polymerizable inks containing radical polymerizable compounds and cationic polymerizable inks containing cationic polymerizable compounds as polymerizable compounds, and both types of inks can be used. . Further, a hybrid type ink in which a radical polymerization type ink and a cationic polymerization type ink are combined may be used. In the first embodiment, a cationic polymerization ink is used among ultraviolet curing inks.
[0034]
Next, the recording medium will be described.
As the recording medium, those made of various types of paper such as plain paper, recycled paper, glossy paper, and the like, various fabrics, various nonwoven fabrics, resins, metals, glass, and the like, which are applied to ordinary inkjet printers, can be used. As a form of the recording medium, a roll shape, a cut sheet shape, a plate shape, or the like can be applied.
[0035]
Next, the operation of the suction device 4 will be described.
When the carriage 2 moves to the maintenance area, the recording head 3 faces the suction device 4. When the recording head 3 descends, the ejection surface 31 of the recording head 3 comes into contact with the suction cap 5. At this time, since the suction cap 5 has elasticity, the suction cap 5 is elastically deformed, and the inside of the suction cap 5 is a space sealed by the inner side surface of the suction cap 5 and the upper surface of the cap holder 6. Then, by activating the suction pump 7, the closed space formed inside the suction cap 5 and the inside of the ink suction pipe 71 become negative pressure, and ink is sucked from the ejection openings of the recording head 3. In the process of sucking the ink, the ink wets the inner surface of the suction cap 5, but since the suction cap 5 is formed of a power fluoroelastomer, it does not swell or dissolve, and the suction cap 5 and the recording head No gap is formed between them. As a result, the space inside the suction cap 5 sucks ink while always maintaining a negative pressure. The ink sucked from the discharge port flows into the ink suction pipe 71 and is discharged to the waste ink tank 72 via the suction pump 7.
[0036]
According to the inkjet printer 100 of the present embodiment, since the suction cap 5 is formed from a perfluoroelastomer having swelling resistance or dissolution resistance to ink, the suction cap 5 can be swelled or dissolved by the ink. In addition, it prevents air from flowing between the recording head 3 and the suction cap 5. That is, at the time of sucking the ink, it is possible to reliably suck the bubbles and the ink in the ejection port in a state where the negative pressure is applied to the ejection port of the recording head 3. A stable image can be output as a printer. Further, since only the suction cap 5 of the suction device 4 is formed of perfluoroelastomer, even if an expensive material such as perfluoroelastomer is used, an increase in the cost of the suction device 4 is minimized. Can be suppressed.
[0037]
Further, since the suction cap 5 has the protruding ridge portion 51 which comes into close contact with the ejection opening of the recording head 3 when sucking ink, the suction cap 5 is applied to the recording head 3 as compared with the case where the upper surface of the suction cap 5 is brought into close contact with the recording head 3. Since the pressure increases, the adhesion of the recording head 3 to the ejection openings can be increased.
[0038]
Further, since the protrusion 52 of the suction cap 5 is received by the receiving portion 8 of the cap holder 6, the movement of the suction cap 5 is regulated by the cap holder 6. As a result, the suction cap 5 does not fall off the cap holder 6.
[0039]
Note that the present invention is not limited to the above embodiment. For example, not only the suction cap 5 but also the cap holder 6 may be formed of perfluoroelastomer. Further, in addition to the suction cap 5 shown in FIG. 3, for example, as shown in FIG. 5, a plurality of (two in FIG. 5) protrusions 51 may be formed. In addition, as shown in FIG. 6A, the overhanging portion 52 may be formed on the inner surface of the suction cap 5, or as shown in FIG. The tip of each ridge 51 may be formed sharp, or as shown in FIGS. 6C and 6D, chamfers 53 are formed on the inner and outer sides of the ridge 51. Is also good. The shape of the receiving portion 8 can be freely changed in accordance with the shape change of the overhang portion 52. In addition, the present invention can be freely changed and improved without departing from the gist of the invention.
[0040]
【The invention's effect】
According to the first aspect of the present invention, since the suction cap is formed from an elastic material having swelling resistance or dissolution resistance to ink, the suction cap does not swell or dissolve with ink, and the recording head To prevent air from flowing in between the air and the suction cap. In other words, when suctioning ink, it is possible to reliably suck air bubbles and ink in the ejection ports while applying a negative pressure to the ejection ports of the recording head. A stable image can be output.
[0041]
According to the second aspect of the present invention, since the suction cap has the ridge portion that comes into close contact with the ejection surface of the recording head when sucking ink, the recording head is compared with a case where the entire suction cap is brought into close contact with the recording head. , The adhesion of the recording head to the ejection surface can be improved.
[0042]
According to the third aspect of the present invention, since the drop-off prevention mechanism for preventing the suction cap from dropping from the cap holder is provided, the suction cap does not drop from the cap holder. Therefore, the reliability as a suction cap is improved, and a stable image can be output as an ink jet printer.
[0043]
According to the fourth aspect of the present invention, since the protrusion of the suction cap is received by the receiving portion of the cap holder, the movement of the suction cap is regulated by the cap holder. The suction cap does not fall off the cap holder due to vibration or the like.
[0044]
According to the fifth aspect of the present invention, even when the illuminance of ultraviolet rays is relatively small, the composition is sufficiently cured, and the deterioration of image quality can be suppressed.
[0045]
According to the invention as set forth in claim 6, since the suction cap is formed from a perfluoroelastomer, the suction cap does not swell or dissolve even when ultraviolet curable ink is used, so that the recording head can be used. In the case of sucking the ink of the ejection port, the bubbles and the ink in the ejection port of the nozzle can be reliably sucked, so that a stable image can be output as an ink jet printer.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a maintenance area of an inkjet printer according to an embodiment of the present invention.
FIG. 2 is a schematic diagram illustrating an outline of a suction device according to an embodiment of the present invention.
3A and 3B are diagrams illustrating a suction cap according to the embodiment of the present invention, wherein FIG. 3A is a perspective view and FIG. 3B is a cross-sectional view taken along line III-III in FIG.
FIG. 4 is a perspective view of a suction cap and a cap holder according to the embodiment of the present invention.
5A and 5B are diagrams illustrating another example of a suction cap according to the embodiment of the present invention, wherein FIG. 5A is a perspective view, and FIG. 5B is a cross-sectional view taken along line VV in FIG.
FIG. 6 is a cross-sectional view illustrating another example of a suction cap according to an embodiment of the present invention.
[Explanation of symbols]
Reference Signs List 3 Recording head 4 Suction device 5 Suction cap 51 Protrusion part 52 Overhang part 6 Cap holder 8 Reception part 100 Ink jet printer

Claims (6)

A recording head having a discharge port for discharging ink on a discharge surface, and a suction device for suctioning ink from the discharge port, comprising:
The suction device includes a suction cap that covers the discharge port of the recording head and is in close contact with the discharge surface when the ink is suctioned, and is separated from the discharge surface when the ink is not suctioned,
An ink jet printer, wherein the suction cap is formed from an elastic material having swelling resistance or dissolution resistance to the ink. 2. The ink jet printer according to claim 1, wherein the suction cap has a ridge that is in close contact with a discharge surface of the recording head when the ink is sucked. The suction device includes a cap holder that supports the suction cap,
The ink jet printer according to claim 1, further comprising a drop-off prevention mechanism for preventing the suction cap from dropping from the cap holder. The drop-off prevention mechanism includes:
An overhang formed along the side surface of the suction cap,
A receiving portion formed on the upper surface of the cap holder and receiving the overhang portion;
The inkjet printer according to claim 3, comprising: The inkjet printer according to any one of claims 1 to 4, wherein the ink is an ultraviolet curable ink containing a cationically polymerizable compound. 6. The ink jet printer according to claim 1, wherein the suction cap is formed from a perfluoroelastomer.

Images